Construction of Cu2O@Cu1.75S Core‐Shell Octahedrons for Enhanced NO2 Gas Sensing at Low Temperature

In this work, fabrication of Cu2O@Cu1.75S core-shell octahedrons was achieved through a facile water bath stirring process. Compared with pure Cu2O, the composite showed enhanced sensing performance for NO2. The response value of Cu2O@Cu1.75S to 5 ppm NO2 at 40 degrees C is seven times that of Cu2O to 5 ppm NO2 at 75 degrees C. Moreover, Cu2O@Cu1.75S has the ability to detect 100 ppb NO2 and has good NO2 sensing selectivity and long-term stability. This study shows that Cu2O@Cu1.75S hybrid is a type of outstanding NO2 gas sensing material on account of its low working temperature and high sensing sensitivity.